The US had Pakistan Taliban chief Hakimullah Mehsud on its wanted list for several years, having indicted him for an attack on its forces in 2009.
A US federal warrant for his arrest was issued in August 2010, when he was charged with conspiracy to murder a US national outside of the country.
Seven US citizens were killed and six injured in the December 30, 2009 attack on a US operating base in Khost Province, Afghanistan, according to the FBI's most wanted list.
Mehsud was killed on Friday by a US drone strike, prompting charges from within Pakistan that Washington intentionally wanted to disrupt a peace overture by the Pakistani government to the group Mehsud led, the Tehrik-e-Taliban Pakistan (TTP).
Just last month, Pakistan's Prime Minister Nawaz Sharif had urged President Barack Obama to end the drone strikes.
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A US State Department official said the issue of such negotiations was an "internal matter for Pakistan.
"More broadly, the United States and Pakistan continue to have a vital, shared strategic interest in ending extremist violence so as to build a more prosperous, stable, and peaceful region," the official said in a statement.
The official also noted that the TTP claimed responsibility for the failed bombing of New York's Times Square on May 1, 2010 and is ideologically closely connected to al-Qaeda. In addition, al-Qaeda relies on TTP for safe haven in the Afghan-Pakistani border region, the official said.
"Given the proximity of the two groups and the nature of their relationship, TTP is a force multiplier for al-Qaeda," the official said early on Sunday.
The US official also noted that the US has designated TTP as a "foreign terrorist organisation" for its continuing terrorist attacks inside Pakistan and for its vows to attack the US and Europe.
